kevo

I had the ATF flushed and changed, and now I want to put synthetic oil in the differientials and transfer case. what brand? I know there is only 1 recomended ATF to use. Does it matter on the diff. oil also?

Lexmex

Actually, all though Toyota Type IV is the official ATF, the other one that also comes up in these discussions is Amsoil ATF, and people who have used this on this forum appear to have been quite happy with it over the Type IV.

As far as gear fluid, I use Royal Purple MaxGear, Amsoil and Redline also have their own fluid. Reason I went with Royal Purple is because they were the only one that could manage to get me the stuff to Mexico, and I actually favored them because a lot of GS owners were also using the stuff and had favorable opinions.

Probably the easiest gear fluid you are going to find is that of Mobil 1, and I have readily seen this available in U.S. auto parts stores like AutoZone. You will need two bottles, one for the rear differential and one for the transfer case.

sktn77a

iTrader: (2)

I guess I'm confused again as to what goes where in these 4WD babies:

ATF in the transmission (presumably)
Gear oil in the rear differential (Mobile 1 75/90?)
Gear oil in the transfer case (?) (Mobile 1 75/90?)
What goes in the front differential (or is that part of the transmission)?
Where is the Limited Slip Differential (front, rear, both, somewhere else)?

(And I thought I knew something about cars...........)

Lexmex

Front differential takes ATF, you fill it through the tranny dipstick and the ATF will go into both the front differential and the tranny. Only difference is that when you drain, the tranny pan has its own plug and so does the front differential.

On left is the front differential plug and on the right is the tranny pan plug.

There is no separate limited slip differential to fill or anything like that, just fill up the rear differential and the transfer case with the gear fluid (Mobil 1 75W90)

sktn77a

iTrader: (2)

Makes sense. So where is the limited slip differential function located - in the rear diff?

(again)

carguy07

Yep, rear diff.

lexus114

Does yours have limited slip?jack up the rear,and rotate the wheel.If they go in the same direction,its limited slip.If one wheel goes in one direction,and the other wheel in the oppisite direction,then its an open rear.

Lexmex

I will likely be changing out my transfer case and rear differential by about April (I like to do it ever year), but this time I will probably be using something other than Royal Purple, due to increased costs/availability issues. I was looking at possibly using the GM synthetic gear fluid (not bad and is similar to the kind of hype that Ford Heavy Duty brake fluid gets).

I'd like to get my hands on some Redline gear fluid this time around, though I can tell you I haven't really been a fan for the past few months of its 10W40 motor oil, I will explain when I finally change it out, though I would actually rate the Mobil 1 0W40 a better oil than this stuff.

I went to the Toyota dealer and all they had was AC Delco gear fluid. BMW sells a 75W140 synethic that I have used to seal up a leak in the transfer case I had before changing out the seals in December.

However, for those of you more fortunate than I am, do use a good quality synthetic gear fluid like Amsoil, Mobil 1, Redline, Royal Purple, etc.

lexus114

I agree with you lex,I tried redline oil too,and dont care for their product.Personaly,I like royal purple,and amsoil.

lexus114

Is it alright to use 0w-40 in our 3.0`s ?

Lexmex

Depends on what W40 you use. For instance, the Castrol 0W30 we talk about has properties similar to that of a 0W40. Mobil 1 0W40 is probably a light W40 and can shear quickly. There is a Liqui Moly 5W40 that a lot of racers use down here, but some find it too heavy and have lost gas mileage, power, but a 5W30 would be okay. Only W40 I ever found okay, was Mobil 1 0W40. I was hoping Redline's would be similar, but it feels a bit heavy. Perhaps, I should give a W30 of theirs a try next time. Castrol 0W30 is till my favorite, though I feel compelled to try different things. There is a Pennzoil Platinum down here, but it is labelled as synthetic due to legal reasons I am sure, but I may give that one a try soon.